Powered pipe flaring tool

ABSTRACT

The powered pipe cutter and the pipe flaring tool both have a piston slidably mounted in a cylinder. The cylinder has a top end closed by a top end plug. A crimped cartridge bore in the top end plug communicates with a gas expansion chamber. A bolt and firing pin assembly are attached to the cylinder top end. The pipe cutter includes a shear housing with a pipe passage connected to the rod end of the cylinder. A shear plate is connected to the piston and moves with the piston to shear pipes. The pipe flaring tool includes a pipe clamp assembly with a pipe passage and a female flaring surface connected to the cylinder rod end. A male flaring surface on the piston cooperates with the female flaring surface to flare pipe ends.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of the filing date of U.S.Provisional Application No. 60/291,405, titled “POWERED PIPE CUTTER ANDFLARING TOOL”, filed May 16, 2001, and U.S. patent application Ser. No.10/147,570, titled “POWERED PIPE CUTTER AND FLARING TOOL”, filed May 16,2002, now U.S. Pat. No. 6,994,009.

TECHNICAL FIELD OF THE INVENTION

The powered pipe cutter and flaring tool are powered by gas from crimpedcartridges, cut pipes to length and flare the cut ends of pipes to formone part of flared pipe connections.

BACKGROUND OF THE INVENTION

Pipes made from metals such as soft copper, rigid copper and steel areused to carry many different liquids and gases. Various tools areemployed to cut these pipes to the desired length. These tools includelathes, grinders, shears, power saws, hand saws and pipe cutters with arolling disk cutter and rollers. A variety of connector systems are usedto connect pipes together. These connector systems include threadedcouplers that attach to threaded pipes, welded joints, solderedconnections, compression connections, and flared connections.

Flared connections are commonly used today for a range of uses. They arerelatively inexpensive, can be subjected to reasonably high temperaturesand pressures, resist leakage of both liquids and gases, and aregenerally reliable.

A range of tools are available for cutting metal pipes to length as wellas flaring the ends of pipes for flared connections. Some of these toolsare large, expensive and non-transportable. Many of the tools requireelectricity. The tools that are transportable and manually operable aregenerally relatively slow, require substantial physical effort tooperate, and frequently fail to produce acceptable results.

Pipe cutters with a rotatable cutter disk and rollers that engage a pipeto be cut tend to reduce the inside diameter of the pipe and can changethe shape of a pipe if the tool user rushes the work too much.

Hand operated pipe flaring tools have a clamp member that engages theoutside surface of a pipe to be flared. Occasionally these clamp membersare not in the correct position relative to the pipe end. The flaringtool engages the clamp member and has a screw that is manually rotatedto advance a conical flaring surface toward the pipe end. These flaringtools require substantial strength on the part of the user. Anexperienced user usually obtains an acceptable flare on copper pipe. Itis much more difficult to obtain an adequate flare on steel lines. Steellines are used for a variety of uses including hydraulic systems formobile and stationary machines. The failure of a hydraulic line on thesemachines may require that the machine be shut down until the line isrepaired. A reliable system for making a replacement line or repairingthe old line, where the machine is located, is needed.

SUMMARY OF THE INVENTION

A pipe flaring tool includes a cylinder with a top end and a rod end. Apiston is slidably mounted in the cylinder. A top end plug with acrimped cartridge bore is on the top end of the cylinder. A bolt andfiring pin assembly are attached to the cylinder top end. A gasexpansion chamber is formed in the cylinder between the head end plugand the piston. The gas expansion chamber is connected to the crimpedcartridge bore. A male flaring surface is carried by a rod end of thepiston and is movable with the piston. A pipe clamp assembly has a pipepassage surrounded by a female flaring surface. The female flaringsurface is in axial alignment with the male flaring surface. The femaleflaring surface is also axially fixed relative to the cylinder.

BRIEF DESCRIPTION OF DRAWINGS

The presently preferred embodiment of the invention is disclosed in thefollowing description and in the accompanying drawings, wherein:

FIG. 1 is a side elevational view of the pipe cutter ready to cut apipe;

FIG. 2 is an expanded elevation view of the pipe cutter;

FIG. 3 is a side elevational view of the pipe cutter with a boltpartially closed and parts broken away;

FIG. 4 is a side elevation view of the pipe cutter with the bolt fullyopen and parts broken away;

FIG. 5 is a sectional view of the pipe cutter with the bolt removed;

FIG. 6 is a perspective view of the small tube diameter flaring tool;

FIG. 7 is a sectional view of the small tube diameter flaring tool withthe bolt broken away;

FIG. 8 is an expanded perspective view of the small tube diameterflaring tools;

FIG. 9A is a side elevational view of the pipe cutter with an openablepipe shear housing;

FIG. 9B is an enlarged perspective view of the pipe cutter with theopenable pipe shear housing closed and parts broken away;

FIG. 10 is a perspective view of the large pipe diameter flaring toolwith the bolt open;

FIG. 11 is a perspective view of the large pipe diameter flaring toolwith the bolt closed; and

FIG. 12 is a perspective view of the large pipe diameter flaring toolwith the pipe clamp open.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A pipe cutter 10 is shown in FIGS. 1-5. A small pipe diameter flaringtool 12 is shown in FIGS. 6-8. A large pipe diameter flaring tool 14 isshown in FIGS. 10-12. All of these tools are powered by a crimpedcartridge 16. The gas expansion chambers 18 and pistons 20 in all threetools are substantially the same. The piston 20 and gas expansionchambers 18 are shown in FIGS. 5 and 7 and will be described first.

The piston 20 is mounted in a cylinder 22. The cylinder has a smoothcylindrical bore 24. A spring abutment flange 26 extends radially inwardfrom the bore 24. A cylindrical passage 28 through the spring abutmentflange 26 is larger than the diameter of the main body 30 of the piston20. A compression spring 32 sets on the spring abutment flange 26 andextends upwardly. A cylindrical flange 34 on the upper end of the piston20 sits on the upper end of the compression spring 32. The diameter ofthe cylindrical flange 34 is slightly less than the inside diameter ofthe cylindrical bore 24.

A cylinder plug 36 is clamped to the top of the cylinder 22 and closesthe top end 38 of the cylinder. A cap 40 with a central opening 42screws onto the cylinder 22 and clamps the cylinder plug 36 in place. Acylindrical inner portion 44 of the cylinder plug 36 has a bottomsurface 46 that abuts an upper end 48 of the piston 20, forces thepiston into the bore 24 and compresses the compression spring 32. Thecylindrical inner portion 44 of the plug 36 is a few thousandths of aninch larger in diameter than the bore 50 in the upper end of the piston20 and separates an inner chamber 54 from the cylinder head end chamber52. An upper axial bore 56 in the plug 36 forms a cartridge chamber. Alower axial bore 58 in the plug 36, is larger in diameter than the upperbore 56, and forms an extension of the inner chamber 54. A valve seat 60is formed at the junction of the upper axial bore 56 and the lower axialbore 58 in the plug 36. A pin 62 on the piston 20 extends upwardlythrough the bore 50 and the bore 58 to the valve seat 60. The pin 62 issmaller in diameter than the lower axial bore 58 to permit free passageof gases into the inner chamber 54 when the pin 62 is out of contactwith the valve seat 60. The pin 62 can contact the valve seat 60 at thesame time the bottom surface 46 of the cylindrical plug 36 contacts theupper end 48 of the piston 20 to seal the inner chamber 54. There can beup to 0.050 inch clearance between the pin 62 and the valve seat 60 andthe piston can perform useful work. A clearance of up to 0.050 of aninch can be between the bottom surface 46 and the upper end 48 of thepiston 20 rather than at the valve seat 60 and the piston can performuseful work. If the clearance in either location exceeds 0.050 of aninch, the piston 20 will not provide the desired force. The pin 62 canbe adjusted axially or the valve seat 60 could be axially adjustable toprovide the desired clearance. Adjusting the clearance between 0clearance and 0.050 of an inch clearance adjusts the force exerted bythe piston 20. It has also been observed that the noise generated by thecrimped cartridge 16 is substantially muffled when the piston exertsmaximum force. When the clearance past the valve seat 60 exceeds 0.050inches the crimped cartridge 16 generates substantial noise.

A crimped cartridge 16 inserted into the upper axial bore 56 seals aprimary chamber 64 between the crimped cartridge 16 and the valve seat60. Gases passing the valve seat 60 enter the large inner chamber 54 andcontinue to expand. Downward movement of the piston 20 moves the upperend 48 of the piston 20 away from the bottom surface 46 and allows gasesto enter the head end chamber 52. This movement of gas between threechambers ensures that substantially all of the propellant in the crimpedcartridge is fully burned and adequate force is exerted on the piston20.

The pipe cutter 10 has a piston extension 66 connected to the piston 20by a bolt 68 that screws into the extension and into a threaded bore 70in the piston. A flat hardened steel shear plate 72 is welded to thebolt 68. The wings 74 and 76 of the shear plate 72 are guided by fourguide plates 78 and a shear housing 80 that is attached to the cylinder22 by threads 82. The shear plate 72 has a lance portion 84 that is offset to one side of a pipe 86 that is to be cut. Shear surfaces 88 and 90extend from the lance portion 84 to the wings 74 and 76. The profile ofthe shear surface 88 is different from the profile of the shear surface90 to obtain a better cut. The pipe 86 passes through bores 92 throughthe shear housing 80. These bores 92 pass through plates 96 that areseparated apart by the thickness of the shear plate 72. A relief 94 inthe plates 96 allows metal sheared from a pipe to fall freely into aretainer cup 98 that screws onto the bottom of the shear housing 80. Thelance portion 84 of the shear plate 72 is off set from the center of thepipe 86 so that it shears the pipe rather than partially collapsing awall of the pipe.

The bolt 100 is pivotally attached to parallel post 102 by a pin 104.The posts 102 are welded to the cap 40. The pin 104 passes through aslot 106 through the bolt 100. The bolt is held in a closed position byan over center linkage 108. The linkage includes two parallel links 110that are pivotally attached to an ear 112 by a pin 114. A handle 116 ispivotally attached to the parallel links 110 by pin 118 and to an ear120 by pin 122. The ear 120 is welded to the cap 40. A cam surface 124on the ear 120 urges the bolt 100 to the left, as shown in FIGS. 1 and2, after the crimped cartridge 16 has entered the cartridge chamber 56and the plastic cartridge holder is held in place relative to thecylinder plug 36.

Pivoting the trigger end 126 of the bell crank 128 counterclockwiseabout the axis of the pin 130, as shown in FIGS. 1 and 2, moves the searend 132 from under the pin 134. This frees the firing pin assembly 136to pivot counterclockwise about the pin 138 under the force of the coilspring 140. The striker 142 strikes a primer on the crimped cartridge 16and the shear plate 72 is advanced and shears the pipe 86 into twopieces. The tubing 144 on the bolt 68, shown in FIG. 5, contacts the topedges 146 of the plates 96 and stops downward movement of the piston 20and the shear plate 72. The tubing 144 is a neoprene spring with aselected spring rate. The spring 32 forces the piston 20 back to theposition shown in FIGS. 1 and 5. The handle 116 is then pivoted to theposition shown in FIG. 4 lifting the pin 134 up over the sear 132. Thislifts the spent crimped cartridge 16 out of the cartridge chamber 56.The handle 116 is then pivoted clockwise about the pin 122 as shown inFIG. 3 moving the pin 134 into contact with the finger 147 on the sear132. Continued clockwise movement of the handle 116 moves the bolt 100to the left until the pin 104 contacts the left end of the slot 106 anda new crimped cartridge 116 enter the cartridge chamber 56. The bellcrank 128 is rotated clockwise about the pin 130 and the torsion spring148 is tensioned. As the bolt 100 closes the new cartridge 16 is held inthe cartridge chamber 56, the cam surface 124 moves the bolt 100 to theleft and the handle 116 moves into a locked position as shown in FIG. 1.

The crimped cartridges 16 can be loaded into the upper bore 56, whichforms a cartridge chamber, manually or automatically as shown in FIGS.1, 2, 3, 4, and 9A. The crimped cartridges 16 can be purchased in aplastic strip 125 with two parallel side edges 119. The side edges ofthe plastic strip 125 are received in grooves in the sides of a channelin the bolt 100 like the grooves 121 in the channel 123 of bolt 336shown in FIG. 10. When the handle 116 is moved, from the bolt 100 in thefully open position shown in FIG. 4 toward the closed position shown inFIG. 1, the bolt moves to the right until the pin 104 contacts the leftend of the slot 106. This advances the plastic strip 125 to the righttogether with the bolt 100. After the next crimped cartridge 16 in theplastic strip 125 is at least partially inserted into the cartridgechamber 56, the pin 114 contacts the cam surface 124, moves the bolt 100to the left, and advances the plastic strip to the right relative to thebolt. The bolt 100 is then in the position shown in FIG. 1 and ready tosever a pipe. After the crimped cartridge 16 in the chamber 56 has beenexpended, the handle 116 is moved counterclockwise about the pin 122 toopen the bolt 100 as explained above. The counterclockwise movement ofthe handle 116 as shown in FIG. 1 first slides the bolt 100 to the leftuntil the pin 104 contacts the right end of the slot 106 and then liftsthe spent crimped cartridge from the chamber 56. This movement of thebolt 100 relative to the pin 104 advances the plastic strip 125 to theright relative to the bolt. As described above, advancing the plasticstrip 125 relative to the bolt 100 to move a new crimped cartridge 16into the chamber 56 takes place in two relatively small steps. It wouldhowever be possible to advance a new cartridge in one large step ifdesired.

The pipe cutter 10 as shown in FIGS. 1 through 5 has a shear housing 80with bores 92 for the passage of a pipe 86 that is to be cut. The bores92 through the plates 96 are for a pipe 86 with a specific diameter. Tocut a pipe 86 with a different diameter, the shear housing 80 isunscrewed from the threads 82 on the cylinder 22 and replaced by a shearhousing 80 with pipe bores 92 that have a diameter that corresponds tothe diameter of the pipe to be cut. The pipe bores 92 receive a pipe 86telescopically only. In some circumstances it is not possible totelescopically slide the shear housing 80 on a pipe 86 to a position inwhich the pipe is to be cut.

FIGS. 9A and 9B show a pipe cutter 10 with a modified shear housing 380.The modified shear housing 380 screws onto the cylinder 22 like theshear housing 80. The plates 396 are severed to form an upper portion382 and a lower portion 384, along a line 386. The line 386 passesthrough the axis of the pipe bore 392. The lower portion 384 ispivotally attached to the upper portion 382 by a hinge with a pivotshaft 388. The pivot shaft 388 is attached to the upper portion 382 andpasses through two ears 390. The ears 390 are welded to the lowerportion 384. A lock assembly 394 locks the lower portion 384 to theupper portion 384 after a pipe 86 which is to be cut is positioned inthe pipe bore 392. The lock assembly 394 includes a locking lever 398that is pivotally attached to a tab 400 by a pivot pin 402. A U-shapedlink 404 has a base 406 that engages a hook 408. The hook 408 is fixedto the upper portion 382. The free ends 410 and 412 of the U-shaped link404 are connected to blocks 414. The blocks 414 are pivotally attachedto the locking lever 398 for pivotal movement about an axis that isparallel to the axis of the pivot pin 402 and the pivot shaft 388. Forceexerted on the locking lever 398 by the U-shaped link 404, when thelocking lever 398 is in a locked position, urges the U-shaped linktoward the locked position. A retainer cup 98 screws to the free end ofthe lower portion 384 to catch material cut from a pipe 86 duringsevering.

The cylinder 22 of the small pipe diameter flaring tool 12 is integralwith a c-shaped pipe clamp holder 150. The pipe clamp holder 150 has apipe clamp passage with a bottom wall 152, a top wall 154 and a backwall 156. A pipe clamp assembly 158 has two clamp bars 160 and 162 thatare pivotally connected to each other by a link bar 164 and pivot pins166 and 168. A two bar yoke 170 is pivotally attached to an end of theclamp bar 160, opposite the link bar 164, by a pivot pin 172. A lever174 is pivotally attached to the yoke 170 by a pivot pin 176. A cam 178on the lever 174 engages the clamp bar 162 and forces both clamp barstogether. A pipe P is inserted into the cooperating half apertures 180with the appropriate diameter and clamped in place by the lever 174. Theclamp assembly 158 and the pipe P is then inserted into the pipe clamppassage with the bar 160 engaged in the wall 156 and an alignment pin182 anchored in the clamp holder 150, received in an alignment passagein the clamp bar 160. An end of the pipe P extends out of the clampassembly 158 as shown in FIG. 7. A passage 184 provides space for thepipe end to move into the pipe holder 150. The passage 184 is also agauge to indicate if the end of the pipe P extends the correct distancefrom the aperture 180. A passage 186 through the bottom wall 152accommodates the long portion of the pipe P. Conical surfaces 188 on thepiston 20 cooperate with conical surfaces 190 at the other end of thecooperating half apertures 180 to form a flared pipe end.

A handle 192 is welded to the cap 40. A bolt 194 is pivotally attachedto a bar 196 welded to the cap 40, by a pin 198. Individual crimpedcartridges 16 are inserted into the cartridge chamber 56 with thisflaring tool 12. A relatively small charge is required to flare smalldiameter pipes. With small charges, the plastic cartridge holder 125 isnot required to extract spent cartridges 16 from the cartridge chamber56. A latch 200 holds the bolt 194 in a closed position.

A firing pin assembly 202 includes a bell crank 204 that is pivotallyattached to the bolt 194 by a pivot pin 206. A striker or firing pin 208is provided on one end of the bell crank 204. A thumb pad 210 isprovided on the other end of the bell crank 204. A torsion spring 212urges the bell crank 204 in a counterclockwise direction as shown inFIG. 6. To flare a pipe P held in alignment with the piston 20, thethumb pad 210 is pressed downward and then released. The spring 212drives the firing pin 208 into a primer in the crimped cartridge 16.

The large diameter pipe flaring tool 14 has a male flaring block 298with a conical flaring surface 300 clamped to the piston 20 by a bolt302. The flaring block 298, which is larger than the cylinder 22, ishoused in a bell housing 304 attached to a lower end of the cylinder 22.The pipe clamp assembly 306 has a first flaring block 308 attached tothe bell housing 304. A second flaring block 310 is pivotally attachedto the first block by pivot pin 312. A recess 314 in the first block 308cooperates with a recess 316 in the second block 310 to form acylindrical bore that is coaxial with the cylinder 22. A flaring diehalf 318 is mounted in each recessed area 314 and 316. Mechanicalfasteners 320 hold the die halves 318 in place. The die halves 318 havea cylindrical pipe clamping surface 322 and a conical flaring surface324. The conical flaring surfaces 324 cooperate with the male conicalflaring surface 300 to flare the end of a pipe P. Handles 326 forclosing the die halves 318, are attached to the first and second flaringblocks 308 and 310. An alignment pin 328 ensures alignment of the twoflaring blocks 308 and 310. After the die halves 318 are closed, thebolt 330 is screwed into the threaded bore 332 and tightened with theclamp handle 334 to clamp the pipe P in place.

The bolt 336 is pivotally attached to the cap 40 by a pivot pin 338 asshown in FIGS. 10 and 11. A latch 340, biased by a spring 341, engages abar 343 and holds the bolt 336 in a closed position. The firing pin 342is fixed to an arm 344. The arm 344 is pivotally attached to the bolt336 by a pivot pin 346. A torsion spring 348 biases the firing pin 342toward the cartridge chamber 56. A trigger lever 350 is fixed to the arm344. A link 352 is pivotally attached to one end of the trigger lever350. When the lever 352 extends downward parallel to the firing pin 342the firing pin 342 is held in a cocked position. When the trigger lever350 and the firing pin 342 are lifted manually and then released,centrifugal force pivots the link 352 to the position shown in FIG. 11and the firing pin 342 strikes the crimped cartridge 16. The flaringblock 298 is advanced toward the end of a pipe P by the piston 20 andexpanding gas from the crimped cartridge 16. The end of the pipe isflared between the conical flaring surface 300 on the flaring block 298and the conical flaring surfaces 324 on the flaring die halves 318. Theflaring die halves 318 fit one size pipe P. Both die halves 318 aretherefore changed when the pipe P to be flared has a different diameter.

The disclosed embodiment is representative of a presently preferred formof the invention, but is intended to be illustrative rather thandefinitive thereof. The invention is defined in the claims.

1. A powered pipe flaring tool comprising: a cylinder with a cylinderbore, a cylinder top end and a cylinder bottom end; a piston slidablymounted in the cylinder; a compression spring mounted in the cylinderand urging the piston toward the cylinder top end; a top end plugmounted on the cylinder top end, a plug central bore passing through thetop end plug and including a crimped cartridge bore portion that iscoaxial with the cylinder bore; a conical male pipe flaring surface on apiston lower end; a gas primary expansion chamber in an upper axial boreof the plug central bore adjacent to the crimped cartridge bore portion,a gas inner expansion chamber inside the piston, and a gas head endexpansion chamber in the cylinder and between the top end plug and apiston upper end; a valve seat inside the plug central bore in the topend plug that cooperates with a piston pin on the piston to control gasflow from the gas primary chamber and into the gas inner expansionchamber; a cylinder plug bottom surface that cooperates with a pistonupper end to control gas flow from the gas inner expansion chamber andinto the gas head end expansion chamber; a bolt and firing pin assemblyattached to the cylinder top end; a pipe clamp assembly with a pipepassage surrounded by a female flaring surface that is axially fixedrelative to the cylinder and wherein the female flaring surface is inaxial alignment with the conical pipe male flaring surface; and whereinthe piston pin moves away from the valve seat and the piston upper endsimultaneously moves away from the cylinder plug bottom surface upon gaspressure in the gas primary expansion chamber moving the piston awayfrom the cylinder top end.
 2. A pipe flaring tool as set forth in claim1 wherein the top end plug is clamped to the top end of the cylinder bya cap that screws onto the cylinder.
 3. A pipe flaring tool, as setforth in claim 2, wherein the bolt and firing pin assembly are pivotallyattached to the cap.
 4. A pipe flaring tool, as set forth in claim 3,including a link pivotally attached to the firing pin assembly in aposition to hold a firing pin out of contact with crimped cartridges inthe crimped cartridge bore.
 5. A pipe flaring tool, as set forth inclaim 1 wherein the pipe clamp assembly includes a pipe clamp holderwith a pipe clamp passage attached to the cylinder and a pipe clampassembly with the female flaring surface mounted in the pipe clamppassage during pipe flaring operations.
 6. A pipe flaring tool, as setforth in claim 1 wherein the pipe clamp assembly includes a firstflaring block fixed to the cylinder, a second flaring block pivotallyattached to the first flaring block, a flaring block clamp operable toclamp the second flaring block to the first flaring block, and the pipepassage is divided along a line of contact between the first flaringblock and the second flaring block.
 7. A pipe flaring tool, as set forthin claim 6 wherein the pipe passage includes a first flaring die halfmounted on the first flaring block, a second flaring die half mounted onthe second flaring block, the female flaring surface is on the firstflaring die half and the second flaring die half, and wherein the firstflaring die half and second flaring die half are changed to accommodatedifferent pipe diameters.